Means for automatically starting and stopping gas engines



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Patented Dec. 21,4 1943 MEANS FOR AUTOMATICALLY STARTING AND STOPPINGGAS ENGINES Joseph A. Numero and Frederick M. Jones, Miri-l neapolis,Minn., assignors to U. S. Thermo Control Company, a. partnershipcomposed of Joseph A. Numro and M. Green Original application November1B. r1939, Serial No.

304,796. Divided and this application Decembei 7, 1942. Serial N0.468,325

(Cl. 29o-2) 6 Claims.

This application relates to means for automatically starting andstopping a gas engine, and has for its object to control the startingand stopping or a gas engine which is a power means for controllingconditions within chambers or the like, such, for example, as means forcon-` trolling the temperature within a chamber generally referred to asair-conditioning.

In arrangements for conditioning where the parts are stationary or thereis large room and availability of sufficient electrical current, it isgenerally customary to furnish the power from an electric motor ormotors. The starting and stopping of electric motors is a simple matterrequiring merely the closing and breaking oi the line circuit throughsuitable switching means. Starting and stopping a gas engine in responseto changes in the condition to be controlled involve seriousdifliculties and uncertainties which have caused it to be regarded asimpractical to use a gas engine for such purposes. Yet in many.

types of industries, such, for example, as the trucking industry, wherespace is limited and4 electric current is unavailable, there is asubstantial need for a satisfactory means for starting and stopping agas engine through changes in the condition controlled by the powerfurnished by the gas engine.

Among these problems are the necessity of using a battery which at thesame time furnishes the current ior the spark of the gas engine and alsoreceives current from the generator operated by the gas engine. Thestarter also must be'oper' ated by the current from the battery, and inpractice the starter itself becomes a generator when the gas engine isoperating. Then in order to insure certain and immediate starting thereis need to use what is called a choke, and yet the choke should bethrown out of operation immediately after the gas engine is started. Allof these instrumentalities must be so related that their control toeiiect starting and stopping by changes of the condition to becontrolled shall be quick and certain.

It is a principal object oi our invention there'- fore to arrange ourbattery, starter-generator, condition-controlled circuit make-and-breakdevice, and a circuit including the make-and-break device and'a masterrelay, so related that when, for example` a circuit is closed by achange of condition to be controlled, as by a change of temperature, therelay will close a circuit through the battery and to thestarter-generator, bringing about the starting oi the motor, and thatthereafter the master relay contacts may serve to generated current.

It is a, further object of our invention to provide a master relay forclosing or breaking the main battery circuit to starter-generator, lincombination with a secondary circuit having battery connection and whichwill be opened and closed by the changing of' the condition to becontrolled and which is adapted to energize the master relay to eii'ectconnection of the battery with the starter-generator i'or starting thegas engine.

It-is a further object oi our invention to provide in connection withthe master relay a secondary relay having very few heavy windings whichin turn go to the master relay in combination with a choke operatingrelay so that when strong current from the battery goes throughio thestarter-generator for starting the motor this current running over a fewwindings will energize the secondary relay to close the circuit throughthe choke relay and operate the choke, but when a weaker generatorcurrent passes back through the heavy wire over the few coils of themaster relay it will be insufilcient to energize the secondary relay andthe choke relay will become deenergized and the choking action broughtto an end.

This application is a division of our application Serial Number304,796', tiled November 16, 1939, Patent No. 2,303,857, grantedDecember 1, 1942.

The full objects and advantages of our invention will appear inconnection with the descripi tion given in detail in the followingspeciiication,

relation one to the other. Fig. l is substantially a reproduction ofFig. 16 of our aforesaid application.

Fig. 2 is a schematic wiring diagram showing the relation of thediierent electrically operated instrumentalities and the) circuitsconnected therewith. Fig. 2 is identical with Fig. 18 of the aforesaidapplication.

Referring to Fig. l wherein the invention is shown applied to means forair-conditioning a compartment, the compartment is indicated at i@ andhas therein a thermostat indicated at II, the wiring from which isshownin Fig. 2, A heat exchanger evaporator I2 isrconnected by duct i3with the compartment I, and another duct it leads from the compartmentID to a blower i5 which connects with ducts not shown for driving airthrough the evaporator heat exchanger I2, the course of the air beingindicated generally by arrows I3' and I4. This arrangement is, as shownin the aforesaid application, one adapted to be applied to thecompartment or a moving vehicle such as a truck, and operates to forceair which goes through the evaporator heat exchanger I2, and thus iscooled, into the compartment and to draw the air from the compartmentthrough passage I4 and thus produce a continual circuit of air withinthe compartment until it has been brought to a desired temperature. Theevaporator heat exchanger when used for cooling is furnished compressedgases from a compressor I6. The travel of this compressed gas normallywill be as follows: From compressor manifold i'i the gas passes throughpipe I8 and reversing valve I9 and pipe 20 to condenser 2i. Fromcondenser 2i the liquiiied gas goes through pipe 22 to compressed gasstorage tank 23.- From the compressed gas storage tank 23 the gas goesthrough pipe 2li to header 25 (shown in dotted lines) for distributingthe gas to the coils of the evaporator heat exchanger, not, shown. Fromthe evaporator heat exchanger the expanded gas returns through pipe 29and valve it, thence through pipe 2i to compressor header 29, where itagain continues the above cycle of distribution. A blower 23 is adaptedto force air through the condenser 2i and thereby remove heat from thecompressed gas in the condenser. The above kmentioned moving parts gettheir power for cp- 'The gas tank 35 furnishes the gas engine withnecessary fuel through pipe 38. A starter generator indicated at 3T -hasits armature, not shown except in the wiring diagram of Fig. 2, fast onshaft 3i). This starter generator by means of the circuitsandarrangement of units, shown in Fig. 2. is adapted to automatically startthe gas engine and to generate electricity for the battery when thecondition to be controlled, in this instance the temperature conditionwithin the chamber i, goes above (or below) a predetermined maximum orminimum.

it will be understood that the valve indicated diagrammatically Vat, i9provides means, not shown, for reversing the flow of the liquid so thatthe hot liquid will go to the evaporator heat exchanger I2` which thusbecomes a heater instead of a cooling device, and the expansion of theliquid will take place in the condenser 2|. This reversal of flowapplies to the present invention only to the extent that, where thereversal of iiow takes place and thc heat exchanger I2 becomes a heatingdevice, the stopping and starting of the gas engine would still becontrolled by the condition of the atmosphere in compartment I0 asaffecting the thermostat I i.

The above dened arrangement of instrumentalities are, as stated, thusapplicable to the airconditioning (by cooling or heating, or both) of acompartment, particularly a movable compartment of a transport vehiclesuch as a truck. And while the arrangement of circuits, relays, switchesand the like, given in detail in Fig. 2, is here shown subject tocontrol by a temperature condition of the air of a compartment, it willbe obvious that it may be employed subject to control from otherchangeable conditions.

Considering now the wiring diagram as illustrated in Fig. 2, thethermostat indicated generally as II may comprise an expansion member 38with a movable contact 39 adapted to engage a iixed contact 40. Thecontact 39 is connected with a wire al, and the contact 4D is connectedwith a wire 42. When the temperature within the compartment I9 is suchas to call for change (either more heat or less heat whichever conditionis required) the instrumentalities operated by the gas engine 29 will berequired to be operated, and, therefore, the gas engine itself will beoperating. When the required condition has been met the contacts 39 andall will separate and the operation of the gas engine will terminate.That is, the closing of the circuit through the wires 4I and 42 will putthe different circuits, relays and the like in condition to cause thestarter generator to start the gas engine and maintain it in operationuntil the condition has changed to a point where the circuit is brokenaticontacts 39, 49, when the gas engine will stop running and operationswill cease. Thus, the closing of contacts 39 and 40 will establish acircuit from battery 43 to starter generator 31, whereby the starter andother instrumentalities will be op` erated to start the gas engine,which will then under normal conditions continue to run until thecircuit is broken at 39, 49 by a change of the condition to becontrolled. The circuit by means the contact between members 46 and 41vand the I motor 37 will thereby be stopped. Wire 48- goes to a movablecontact member 49 which engages a contact 5D connected with a wire 5I.The movable contact piece 49 is pivoted at 52 and is held in contactwith member 5D by a spring 53. A pressure tube 54 runs from the hotiluid manifold 28 of compressor I6 to a pressure responsive device 55which has a plunger 5B adapted to engage an arm 51 fast with the movableContact arm 49. Normally contacts 49 and 50 will engage to complete thecircuit from wire 5I to wire 38. When, however, the pressure in thecompressor system rises to approach the danger point the plunger 55 willengage the arm 57 and cause breaking of Contact between contact members49 and 5B. thus causing the gas engine to stop and, inturn, stoppingoperation 4of the compressor. Gages 59, 59' are connected by branchpipes 6U and 60 with the pressure tubes '5d and 6I and indicate to theoperator the pressure at which the compressor is working. A low pressuretube 5I leads from the low pressure manifold I1 of compressor I6 to apressure resistance device 62. This embodies a plunger 63 against whichan arm 04 is held by means of aspringBS. An arm 66 is movable with arm64 about a point of pivoting 61, and when the pressure within the systemdrops to indicate blocking from freezing the plunger 63 will beretracted by the spring 65, which will rock arms 64 and B6 to bring arm66 against arm 51 and also break the contact between members.49 and 50.The wire 5| is connected through branch wire 58 with a high tension coil68 which is connected in a usual manner through cable 69 with thedistributor and ignition system of the gas engine, not shown. The wire5| is also connected with the windings of a relay which is referred toherein as the master relay and which will be described as to detail anduse hereinafter.

Continuing to trace the circuits through, with the intervening safetydevices, the wire 42 normally extends to a contact 1| adapted to engagea contact 12 on a spring-held double contact arm 13 secured to framepiece 14 and connected to a wire 15, The wire 15 passes through aresistance winding 16 which engages a thermostat piece 11. A hook 18 onthermostat piece 11 engages a hook 19 on double contact arm 13. Thisresistance winding 16 is in a branch circuit including a wire 80 whichruns to a contact member 8| adapted to engage another contact member 82connected by a wire 83 with a relay 84 and from the relay 84 with aground 85. The purpose of this arrangement has to do with operation of achoke, which will later be described. The object of the thermostaticmember 11 and heat resistance 16 is to throw the system out of operationwhen current continues for tooA long a period to pass through thecircuitl including the wires 80 and 83 and the relay 84. l

With all of these' instrumentalities in their normal closed position andthe thermostat contacts 39 and 40 brought to closing position becauseheat exchange operation is called for, a branch wire 86 from the mainbattery wire 81 will carry battery current through wire 81, bridge piece13 past contacts 1|, 12 through wire 42, past contacts 39, 40 throughwire 4|, past contacts 46 and 41 through wire 48, past contacts 49, 50through wire 5| to master relay 10 and finally to ground 88, thusenergizing master relay 10 and closing contacts 89, 90. This causesheavy battery current to pass through branch wire 9| connected with mainbattery wire 81 and through -wire 92, relay 93 and wire 94 therefrom,through the field coils 95 of the starter motor armature 91 and toground 98. At the same time current will pass through a rheostat 99 andwire |00, through generator field coils 96 and thence through wire |0|to the armature 91, thereby caused to generate current going t0 battery43.

There are but few windings on relay 93. These windings carry the heavybattery current from wires 9|, 92 going to the starter generator andlikewise carry the weak generator current going back through wires 94,92, 9| and 81 to the battery. The few windings of relay 93 when carryingthe heavy battery current will energize the relay to the point ofoperating the armature |02 thereof. But when the weaker` generatorcurrent passes through relay 93 the few windings will not produce anenergizing of relay 93 so that it is sufiiciently energized to movearmature |02 and close circuits 8| and 82 only when heavy batterystarter current is going to the eld coils 95.

This is an important feature of our invention since the certainautomatic starting of a gas engine requires choke operation, and at thesame time calls for instant termination of choke operation when themotor is started. As heretofore pointed out, closing of circuit throughcontacts 8| and 82 causes current to ow through relay 84 to ground 85.This pulls down the armature |03 on arm |04 pivoted at |05 and normallyheld up by spring |06. A link |01 having an elongated slot |08 connectswith a pin |09 on arm ||0 which operates choke The arm ||0 is abimetallic thermostatic arm, so that when the engine is hot, and thereis no need of choking action on starting the engine, the thermostatcaction of arm ||0 will move pin |09 down slot |08 so that when relay B4is energized for starting the motor it will not have any effect on chokevalve I As above pointed out, battery current goes from branch wire 58through high tension coil 68 and distributor cable 69 to the ignitionsystem of the gas engine, and this circuit will remain closed foroperation of the gas engine until broken by the action of the thermostatseparating contacts 39 and 40 or by the action of any of the safetydevices above described. The current going to the high tension coil 68passes to the ground ||2.

There are other conditions to be contrcied adapted to operate throughinstrumentalities powered by a gas engine, as, for example, a conditiondependent upon air pressure in the apparatus of the aforesaidapplication. When air is drawn in by the blower |5 through the coils ofthe heat exchanger |2, as indicated by the arrow |3, the space ||3, seeupper left of Fig. l, will be subject to negative air pressure whichwill be increased when the spaces between the coils of the evaporatorheat exchanger are clogged with frost. In that arrangement the valve |9is operated through an electrical hookupwith a device in said space ||3so as to reverse the flow of refrigerant and heat the coils and causethe frost and ice thereon to be melted. This is accomplished by means ofan aneroid ||4 which controls a contact piece ||5 closing contacts ||6,||1, which closes a circuit to ground ||8 from wire ||9. Expansion ofthe aneroid ||4 through decrease in air pressure surrounding it causescontacts ||6 and ||1 to engage, permitting battery current to flowthrough a branch wire |20, relay 2| and wire i9 to ground H8. This pullsup the armature |22 which simultaneously closes a set of contacts |23,|24 and |25 and at the same time will open contacts |26, |21 and |28. Amotor comprises armature |29 and eld coils |30. A wire |3| goes fromground |32 through armature |29 and wire |33 to contact bar |34 by whichcontacts |25 and |28 are circuited. Another wire |35 goes from eld coil|30 to bar |36 circuiting contact |21, and a wire |31 goes from theother end of eld coil |30 to contact bars |38 and |39, circuitingrespectively contacts |24 and |26. A branch wire |40 goes from wire |35to contact bar |4| circuiting contact |23, and a wire from contact bar|42 between contacts |24 and |21 goes to ground |44. Branch wire |45leads from battery Wire 81 and connects with another wire |46 havingthereon a contact |41. Another contact |48 is connected with wire |49which goes to contact bar |50. A bridge piece |5| is adapted to closethe circuit through contacts |41, |48, as shown in the lower right-handportion of Fig. 2.' The wire |45 also has thereon a contact piece |52.Another contact piece |53 is connected with a wire |54 which goes toContact bar |55. The

gap between contacts |52 and |53 is adapted to be closed by a bridgepiece |56.

The motor |29,r |30 is a standard reversing motor having the abovedescribed two sets of current wires |3|, |33 and |35, |31. When by themeans above described the current is caused to travel in the directionof the arrow a the motor will turn in one direction, and when thebattery current is caused to travel in the direction of arrow b themotor will be reversed and turned in the opposite direction. An arm |51von a shaft |58 driven by the motor is adapted in one position to contacta linger y|59 on bridgev piece |56 to break the circuit between contacts|52 and |53, as shown, and stop operation of the motor |29, |30 when ithas turned the shaft |58y through an arc of 90 degrees. The arm |51 islikewise adapted to engage a linger |50 on theA Y bridge piece so whenthe current is reversed by energizing the relay |2| acircuit isreestablished between contacts |52 and |53 and at the end of a 90revolution of shaft |53 the bridge piece |5| will be moved to break thecircuit between contacts |41 and |48. As above pointed out theenergization of relay |2| takes place when the pressure conditionchanges so that aneroid l I4 causes'contacts H6 and to engage. When thecondition, as increase of air pressure, changes the arrangement ofcircuits and relays in relation to the starter-generator and the chokeof the gas engine is such as to produce certain quick starting to befollowed by immediatethrowing out of the starting mechanism and actionof the generator.

We claim: l. Means for automatically starting and stopping a gas enginein response to changes of conditions to be controlled, comprising astarter motor adapted to act as a generator, a battery for operating thestarter motor and for receiving curso that the aneroid causes a breakingof the ciring about a change for stabilizing of the condition l to becontrolled. n

Another type of control may be effected by humidication. As shown in thecenter left-l hand part of Fig. 2, a branch wire |6| leads to l Iture,pressure andthe like, including a gas engine for operating the same,means for automatically starting and stopping the gas engine in closethecircuit through contacts ld and the heater will be put into circuitand will vaporizje moisture to be thrown into the air to increase itshumidication. When the humidication reaches the desired predetermineddegree the humidostat will break the circuit between contacts i6@ and|65 and terminate further condition of moisture to the air in thecompartment, it being noted that the humidostat v|66 is posin tloned ona wall of the compartment, as indicated diagrammatically in Fig. 2.

A manual switch indicated at |16 may throw the entire system out ofoperation in a customary way.

In general the operation of the Various instrumentalities has been quitefully given in connec- A tion with their detailed description. Anexample of the use of the invention is illustrated in Figrent generatedby the generator, a master relay for closing the circuit between thebattery and the starter generator motor, a secondary circuit connectedwith the battery and with the ignition system of the gas engine and withthe master relay for energizing the master relay and providing ignitioncurrent to the 'gas engine, and a.

member in said secondary circuit operated by external changes, as oftemperature, pressure and the like adapted to close and break thesecondary circuit in response to such changes of a predetermined amount,said secondary circuit remaining closed and active to hold the masterrelay operative until the member breaks the secondary circuit, thecircuit through the master relay contacts carrying battery current forstarting the gas engine and thereafter carrying generated current to thebattery for charging the same.

2. In means for controllingchangeable conditions within a closed chambersuch as temperaresponse to changes of condition within such chamber,comprising a starter motor adapted to act as a generator, a battery foroperating the starter motor and for receiving current generated by thegenerator, a master relay for closing the circuit between the batteryand the starter lgenerator motor, a secondary circuit connected with thebattery and with the ignitionl system of the gas engine and with themaster relay for energizing the master relay and providing ignitioncurrent to the gas engine, a member in said secondary circuit operatedby such changes of condition external thereto adapted to close and breakthe same in response to such changes of va predetermined amount, saidsecondary circuit vremaining closed and active to hold the master relayoperative until the change-responsive member breaks the secondarycircuit, the circuit closed by the master relay carrying battery currentfor starting the gas engine and thereafter carrying generated current tothe battery for charging 3. Means for starting and stopping a gas enginein response to changes in a condition to be controlled. such astemperature, pressure and the like, comprising a starter motor adaptedto act as a generator, a battery for operating the starter motor and forreceiving current generated by the generator, a high current circuitfrom the battery to the starting generator including contacts of amaster relay and a second high current relay, said second relay havingfew windings so that only high current will energize it, a choke andmeans for operating it including a circuit from said second relay activeonly when said second relay is energized, a secondary circuit connectedwith the battery and the ignition system of the gas engine and with oneof said relays, a member for said secondary circuit operated by suchchanges of condition external thereto adapted to close and break thesecondary circuit in response to such temperature changes ofpredetermined amount, said secondary circuit remaining closed and activeto hold the master relay operative until the member breaks the secondarycircuit, the circuit closed by the master relay and through the secondnamed relay carrying high battery current for starting the gas engineand energizing the second named relay to cause operation of the choke,and thereafter carrying weaker generated current to the battery forcharging the same while resulting in deenergizing of the second namedrelay.

4. In means for controlling temperature within a compartment, includinga compressor and airmoving means, and a gas engine for operating thesame, a starter generator, a battery and a circuit therefrom to thestarter-generator including a circuit-breaking switch, a master relayfor closing said switch when the master relay is energized, a batterycircuit running to the master relay and to the distributor for theignition system of the gas engine, a switch in said last-named circuit,and a thermostat in said compartment responsive to the temperaturecondition therein to be' controlled by means operated by the gas enginefor operating said switch to make or break the last-named circuit,whereby battery current will be caused to go through closed contacts ofthe first-named switch to the starter-generator and generator currentwill pass through said same closed switch to the battery after the gasengine has been started.

5. In means for starting and stopping a gas engine, a starter-generator,a battery and a circuit therefrom to the starter-generator including acircuit-breaking switch, a master relay for closing said switch when themaster relay is energized, a. battery circuit energizing said masterrelay including a switch, a member responsive to external conditions to,be controlled by the operation of the gas engine such as temperaturefor operating said switch to make or break the lastnamed circuit, heatresponsive members in said last-named circuit for breaking the circuitwhen excessive heat takes place, said last circuit re- `maining closedand the master relay energized until the last-named circuit is broken byoperation of its switch by the members responsive to the condition to becontrolled, whereby the battery current will be caused to go through theclosed contacts of the first-named switch and weaker generator currentafter the gas engine has been started will pass through the closedswitch of the master relay to the battery.

6. In means for starting and stopping a gas engine, a starter-generator,a choke, a battery and a circuit therefrom to the starter-generatorincluding a circuit-breaking switch, a choke circuit, a choke circuitrelay in said battery circuit having but few windings, a master relayfor closing said switch when the master relay is energized, a batterycircuit for energizing said master relay including a switch, a memberresponsive to conditions to be controlled through operation of the gasengine for operating said switch to make or break the last-namedcircuit, and a relay in said choke circuit for operating the choke,whereby battery current will be caused to go through the closed contactsof the master switch and through the few windingsiof the choke circuitrelay and thereby energize the same and after the gas engine has beenstarted weaker generator current will pass through said few windings andsaid closed switch to the battery, said generator current being too weakto energize the choke circuit relay so the choke relay will bedeenergized and the choke be put out of commission.

JOSEPH iA. NUMERO. FREDERICK M. JONES.

